The present invention relates to a system for displaying a standard NTSC video signal having an aspect ratio of 4:3 on a wide screen having an aspect ratio of 16:9, and more particularly to a method for reducing no-signal areas appearing on both sides of a wide screen by varying a time compression ratio of a video signal, and a corresponding apparatus.
Generally, an aspect ratio of the typical NTSC television is 4:3, while an aspect ratio for maximizing actual presence to a viewer is 16:9. Several methods are being proposed for displaying the standard NTSC broadcasting signal or a VTR signal of visual system transmission algorithm (VISTA) size on a television receiver having the aspect ratio of 16:9.
FIGS. 1A to 1C illustrate examples of presenting an NTSC signal having the aspect ratio of 4:3 on the television receiver of a 16:9 aspect ratio. In FIG. 1A, when the video signal is displayed by performing a time compression, the video signal of 4:3 can be reproduced on the screen of 16:9. However, the video signal is insufficient and an empty space is produced on the right and left portions of the screen during a horizontal scanning period.
In FIG. 1B, when the NTSC broadcasting signal of 4:3 is displayed on the screen of 16:9 without performing time compression, the picture broadens by 4/3 times in the right and left directions of the screen to make a viewer feel that the picture is being lost.
Also, when displaying the NTSC broadcasting signal of 4:3 aspect ratio in a cinema mode, a deflection treatment expands the picture upward and downward to cut the upper and lower portions as shown in FIG. 1C.